Total phenolic compounds,antioxidant potential and α-glucosidase inhibition by Tunisian Euphorbia paralias L.

Objective:To examine the potential antioxidant and anti-α-glucosidase inhibitory activities of Tunisian Euphorbia paralias L.leaves and stems extracts and their composition of total polyphenol and flavonoids.Methods:The different samples were tested for their antiradical activities by using 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS)and 1,1-diphenyl-2-picrylhydrazyl(DPPH)assays.Inα-glucosidase activity,α-glucosidase(0.3 IU/mL)and substrate,2500μmol/L p-nitrophenylα-D-glucopyranoside were used;absorbance was registered at 405 nm.Results:The leaves acetonic extract exhibited the strongestα-glucosidase inhibition[IC_(50)=(0.0035±0.001)μg/mL],which was 20-fold more active than the standard product(acarbose)[IC_(50)=(0.07±0.01)μg/mL].Acetonic extract of the leaves exhibited the highest quantity of total phenolic[(95.54±0.04)μg gallic acid equivalent/mg]and flavonoid[(55.16±0.25)μg quercetin equivalent/mg].The obtained findings presented also that this extract was detected with best antioxidant capacity[IC_(50)=(0.015±0.01)μg/mL]against DPPH and a value of IC_(50)equal to(0.02±0.01)μg/mL against ABTS.Positive relationship between polyphenolic content of the tested Euphorbia paralias L.leaves and stems extracts and its antioxidant activity(DPPH and ABTS)was detected.Elevated positive linear correlation was got between ABTS and total phenolic(R^(2)=0.751).Conclusions:The findings clearly demonstrate that the use of a polar solvent enables extraction of significant quantities of phenol compounds and flavonoids.